Circuit-breaker.



UNITEDL STATES.

JOsn'Pn Laces, oFsoHENEorAnY, NEW YORK, AssieNOR To aLEo'raie OOMPANY, AOORPORATION OF :New YORK.

Be it known that I, JOSEPH LA Cos, a citilzen of the United States, residing at Schenectady, county of Schenectady,v State of New York, have invented certain new and useful Improvements in'Circuit- Breakers, of which the following is a'specification.

his invention relates to electric switches, and especially to vthose whicltare' provided with' an overload tripping-coil by which they are automatically opened'in casel an abnorheavy ',cur'rent comes on the circuit.

`'Ihe tripping-coil is usually arrangedto attract a pivoted armaturerwhich is connected by a-rod with'a pivoted'latch 'engaging'with an arm on a movable contact-'carrier controlling the circuit. A"spring urges 'the carrier in a direction to o en the circuit when the .latch is disengaged o'm the arm.. The latch tooth-having a V- is armed with a hard-steel shaped edge. In cirlcuitbreakers as heretol. within certain limits. breaker is, close'dthe dog cants downward, so

fore constructed this tooth ab'uts against the. free end of a dog of case-hardened steel pivoted en the arm andca able of vibrating iihen the circuitthat its meeting-point with the tooth ofthe nach is Sighuyielow the une joinmgthe pay- .ots of the latch anddog. These two parts,

therefore, form a' locked toggle. latch is lifted by thel overload-coil, 'the'dog tiltsupward, the toggle Ais broken, and the tooth of the latch slips olf -the'end ofthe dog and leaves the switch free to be opened by sa .f It as beenfound thatmcase the dog ha pens to be soft from faulty hardening t e. .sharp end Athe s rin of the tooth is liable tol cut-into it,

- sothat the tooth Will notslip off and release the switch. This is likely to cause serious rdamage by preventing the opening ofthe circuit 'on an overload; and' the obj ect of my invention is to remedy the trouble by providing a latch-engagmg device which cannot 'possi- 'bly stick vand is absolutelv 'sure to release. In' the accompan ng. rawings, Figure 1 is a front elevation o a circuit-breaker, partly v broken away todisclose my invention; and

Fig:R 2 shows a modification. he several parts are nearly all of standard construction and need notb'e described in deytail, 4'On the frame of the'overload-coil 1 is `pivoted the latch 2, connected by the rodl 3 .v'vithrthe pivoted armature 4 of the coil, as

When' the PATENT OFFICE.

( EN ERAL ClFlCUlT-BREA'KEF?.

Speci-cation of Letters Patent. Application filed August y25. 1904. Serial No. 2221082.

Patented May 1. 1906.

usual. The latch is armed with the cus-v tomary hard-steel tooth 5, having a V-shaped edge.' In the arm @which projects from the pivoted contact-carrier 7, is-pivoted a cylin-' drical roller 8, preferably of hardened steel. The latch has a horn 9, which rests on the roller when the 'switch is closed ,O as shown 1n the drawings, the parts being arrested with breaker constantly urges the arm 6 toward the left vand presses the roller against the tooth. This tends to force the latch downward;.but this tendency is resisted bythe horn 9, so that the arts-remainlocked in the position shown.v hen an overload comes o rnthe coil attracts its armature withsuffl;

cient strength'to overcomethe tension of the spring 12,'and by means ofthe rod 3 it lifts t elatch. VThe instant the. point` of the tooth rises above the dead-center line joining the pivots of the latch and the roller thepressure exerted by the openingfs rin throws the arm 6 to the left, and the toot ri es up on the.

roller, which turns freely and offers no resistance to the movement of the arm. It will thus be seen that no matter how deeply. the toothv may. bite into the periphery 0i the roller the parts cannot lock above the dea dcenter` line, and hence the circuitfbreaker is always sure to o en. In the mod` cation shown in F' spring l1 is dispensed With and in'p a light helical springl abutting between the of the armature 4. The adjusting-nut 15 on the rod 3 is set to leave some play between itself and the arm 14 when the parts stand in the position illustrated.. TheVA armexerts suficientLpressure von the spring to cause it to 2 the, ace or it hold the latch down with enoughforce toene gage prom tly with the arm '6- when the switch is c osedybut when the breaker is' is placed'on the rod 3,y latch and the arm 144 roo roller, and a horn on said latch adapted hammer-blow. Moreover, the spring 13 does not 'put any' additional load on the coil 1, whereas the flat spring Il does exert a constant load thereon.

In accordance vwith the provisions of the patent statutes, I have described the principle of operation of my invention, 4together with the ,apparatus which I now consider to represent the best embodiment thereof; but I desire to have it understood that the apparatus shown ,is only illustrative and. that the invention 4can be carried out by other means.`A l What I claim as new, and desire to secure by- Letters Patent of the United States, is

1. The combination with a pivoted arm, of a'roller pivoted in said arm, a pivoted latch. having a` tooth to engage the periphery of the to rest on said roller.

2. In a circuit-breaker, the combination with a movable element,oil a roller pivoted therein7 a pivoted latch having a tooth engaging withl the periphery of said roller, and means for engagin the'roller to arrest said parts with the toot just below the line join- `lng the pivots of the roller and the latch.

y3. In a circui't-breakwr7 the combination vith the movable contact-carrier, of an arm thereon, a roller pivoted in said arm, and a. latch to hold the circuit-breaker closed, provided with a\.tooth.bearing against the periphery of said roller.

4. In a circuit-breaker, the combination 'with the movable contact-carrier, of an arm thereon, a roller pivotediin said arm, a latch to hold the circuit-breaker closed, provided with a tooth bearing against the periphery of said roller, and ahorn on said latch to rest on said roller. D

5. In a circuitbreaker, the combination with a pivoted -latch and an overload-coil ar- -In witnesswhereof I have' hereuntoset my vhand this 24th day ofAugust, A1904.

v J OSEPH LA COS'.

Witnesses:

BENJAMIN4 B. HULL,

HELEN OnFoRD. 

